The field of the present invention relates to machines which produce light displays, specifically to those machines that utilize both movement of a light source and the phenomenon of persistence of vision to produce visually striking, intriguing, and/or pleasing light displays.
This application may be related to subject matter disclosed in:
U.S. Pat. No. 5,844,377 entitled “Kinetically multicolored light source” issued Dec. 01, 1998 to Matthew E. Anderson and Thomas A. Hughes;
U.S. Pat. No. 6,239,774 entitled “Persistent image maker” issued May 29, 2001 to Altman;
U.S. Pat. No. 6,016,038 entitled “Multicolored LED lighting method and apparatus” issued Jan. 18, 2000 to Mueller et al;
U.S. Pat. No. 5,418,697 entitled “Signal lamp assembly for bicycles” issued May 23, 1995 to Chiou;
U.S. Pat. No. 5,406,300 entitled “Swing type aerial display system” issued Apr. 11, 1995 to Tokimoto et al;
U.S. Pat. No. 5,145,444 entitled “Strobe light effect yo-yo” issued Sep. 18, 1992 to Vankuiken;
U.S. Pat. No. 5,066,929 entitled “Circuit for producing four indications on a bicolor light emitting diode having two leads” issued Nov. 19, 1991 to Frantz;
U.S. Pat. No. 5,057,827 entitled “Means and method for producing an optical illusion” issued Oct. 15, 1991 to Nobile et al;
U.S. Pat. No. 5,032,098 entitled “Illuminated flying disk” issued Jul. 16, 1991 to Balogh et al;
U.S. Pat. No. 4,810,937 entitled “Multicolor optical device” issued Mar. 7, 1989 to Havel;
U.S. Pat. No. 4,754,202 entitled “Multicolor comparison display” issued Jun. 28, 1988 to Havel;
U.S. Pat. No. 4,298,868 entitled “Electronic display apparatus” issued Nov. 3, 1981 to Spurgeon; and
U.S. Pat. No. 4,038,611 entitled “Variable on- and off-time relaxation oscillator” issued Jul. 26, 1977 to Greig.
Displays of brightly colored light have almost universal appeal, and the development of techniques for their production has absorbed much inventive effort. At the opposite end of the size spectrum from fireworks displays and laser light shows, there are many machines that enable the production of small, person-sized light displays. A study of the smaller devices reveals a number of schemes for making colored light appear to emanate from various points in space. These displays, being generated for the benefit of humans, typically exploit various of the known characteristics of the human visual system.
The effectiveness of many light displays rests upon the phenomenon of persistence of vision, that is, the visual memory that persists for a moment after the associated visual stimulus has been removed. Thus a light source rapidly moved within an otherwise darkened room will cause a bright trace to persist in the vision of an observer after the passing of the light source. This phenomenon can be exploited with any light source having adequate contrast against its background, but the images are most striking when a variety of colors and stroboscopic effects are used. Furthermore, images appearing to be extended, multidimensional, illuminated displays can thereby be produced with only a small number of discrete but rapidly moving light sources.
A light source capable of producing light of only a few primary colors may be made to appear to emit a nearly infinite range of secondary colors by rapid oscillation between two or more primary colors; if the light source does not move with respect to the observer's field of vision, at oscillation frequencies above 10 Hz, a constant, secondary color will be observed. This is another exploitation of the phenomenon of persistence of vision. An example of such a device is described in U.S. Pat. No. 5,066,929, which discloses a light source comprising a pair of LED's each emitting a primary color and both contained in a single contiguous translucent housing. By connecting the LED's in parallel with opposite polarities and applying an alternating signal across them at sufficiently high frequencies, both primary colors are alternately produced but appear to a human observer as a single secondary color. The relative contributions from each of the two primary colors to the secondary color are dependent upon the duty cycle and the amplitude of the alternating drive signal, and the electrical response of the LED's. By varying the drive signal, the secondary color may be continuously varied.
When a light source alternately pulsing at least two primary colors to produce the visual effect of a constant secondary color moves with sufficient speed across an observer's field of view, the secondary color appears to separate into its constituent primary colors. More specifically, each primary color will produce a streak of color that persists momentarily in the observer's vision and the secondary color will no longer be apparent. This occurs whenever the pulsating light source moves fast enough that the distances traveled during an “on” cycle of a primary color are visually resolvable. This effect can be used to generate a kinetically multicolored light source which appears to emit a constant secondary color when stationary and multiple primary colors when moving (as in U.S. Pat. No. 5,844,377).
Machines that rely on persistence of vision in order to make operator-selectable or operator-controllable light displays must address the problems of how to simultaneously move and power the light sources and how to provide the operator with control over the delivery of power to those sources. The motion of the light sources must be fairly rapid (depending upon the desired visual effect) and the control element typically requires a number of electrical connections to the moving light sources. These problems may be solved with rigid mechanical members moving the light sources and brush-type electrical contacts, but such a solution is expensive and cumbersome. If a particular display is desired, there must be controls to synchronize the light emission with the motion of the light sources. This may be achieved with brush-type connections, with acceleration-sensing devices, or with some other form of feedback from the light source. However, this may contribute heft and/or complexity to the device, and generally increase the manufacturing cost. There must also be an operator interface allowing the operator to control the light display. It is best that this control be exercisable even as the machine moves and that associated requisite manipulations, such as pushing buttons or moving sliding switches, be uncomplicated.
Application of the above techniques to the production of light displays are described in a number of U.S. Patents. Two relatively complicated machines, which include rotating parts and brush-type electrical connections, are described in U.S. Pat. Nos. 5,057,827 and 4,298,868. These machines generate a large number of light displays, but their use is restricted by their bigger-than-pocket size, mechanical and electrical complexity, and associated manufacturing cost. U.S. Pat. Nos. 5,844,377, 5,406,300, and 6,239,774 describe hand-held devices which generate light displays when a light-emitting component is simply waved through the air. These do not disclose an inexpensive electronic means for generating a large number of many-colored light displays: Pat. No. 5,844,377 does not disclose any electronic means for the operator to control the production of light displays; Pat. Nos. 5,406,300 and 6,239,774 discuss the production of specific images as opposed to colorful and attractive patterns and do not disclose a suitable interface for the production of numerous colorful displays. U.S. Pat. Nos. 5,145,444, 5,418,697, and 5,032,098 describe the mounting of a light source onto a “yo-yo”, bicycle wheel, or flying disk, respectively, in order to generate the movement required for a persistence-of-vision-type light display; though these inventions may produce many distinctive and colorful displays, they lack a means for an operator to control the production of light while the machine is in motion, so an operator-controlled, uninterrupted production of a series of changing light displays is not possible.
Machines for producing colorful light displays which include a moving light source and rely on the phenomenon of persistence of vision to create an appealing visual effect typically include an electric circuit which powers the light source in a time dependent manner. The specifics of the generated light display are dictated by the simultaneous driving and moving of the light source. There are continuing efforts to produce light displays with ever greater visual appeal and to reduce the cost of the associated driving circuitry.